Method of well construction.



PATENTBD DEC. 4, 1906.

D. M. SWAIN. METHOD OF WELL CONSTRUCTION.

APPLICATION FILED OCT. 23, 1905.

of sand with the drill remove DAVID M. SWAIN, OF STILLWATER, MINNEsoTA.

METHOD OF WELL CONSTRUCTION.

Specification of Letters Patent;

Patented Dec. 4, 1906'.

Application filed October 28.1906. Serial No. 284.008.

I an overlying and an underlying stratum of cla ifiiculty has been experienced in sinking or construct' owing to the act that as soon as the drill reaches the as-bearing stratum the pressure of the as Wlll drive the sand and gravel out throug the well-casing and remove the support for the superincumbent clay. The overlying clay being thus deprived of its support will sag or drop down until it meets or nearly meets the underlying impervious stratum,

and thus block the passage of the gas into the well-casing. It is particularly the purpose of my method of construction to prevent the passage for the gas from being thus blocked.

To this end my invention consists in the method hereinafter particularly described and claimed.

In the accompanying drawings, forming part of this specification, Figure 1 is a sectional view of a well-casing in use in an earth formation of the kind described, showing the drill just entering the gas-bearing stratum of sand or gravel. Fig. 2 is a similar view of the casing driven entirely throu h the stratum f. Fig. 3 is a similar view w th the casing withdrawn above the stratum of gas-bearing sand. Fig. 4 is a sectional view of a well-casing where the drill has penetrated the'stratum of sand or. gravel and the overlying stratum of clay has been deprived of its support; and Fig. 5 is a sectional view of the same: after the drill has been withdrawn, the obstructing portion of the overlying clay removed, and the passage for the gas filled with sand or avel.

In the drawings, A and represent, respectively, an. overlying and an underlying stratum of clay or other impervious material,

and Crepre'sents an intermediate'stratum of. gas-bear ng sander gravel. 5S

ordinary tubular casingf2 and'appropriate In the practice of my. met

gas-wells in such formations,

hodI employ an.

drill 3, which works within the casing. In

' Fig. 1 I have shown the drill driven down so as just to reach the gas-bearing stratum, the drill of course being slightly in advance of thelower end of the casing. As soon as the drill reaches the gas-bearing stratum the gas will rise in the casing, and if the apparatus were permitted to remain in that position the gas would blow out the gas-bearing sand and gravel and permit the overlying clay to fall, as illustrated in Fig. 4. Therefore as soon as the rising gas is detected the drill is withdrawn and casing is driven down entirely through the stratum of gas-bearing sand or gravel into the position shown in Fig. 2. he material in the casing is then drilled out, and sufficient cement is dropped to the bottom of the well to form a seal 4 to prevent the possibility of water working up into the easing and obstructing the flow of gas. A

The next step in my improved method is to fill the lower-part of the bore with means pervious to the flow of gas which will prevent the blowing out of the gas-bearing stratum. I prefer to accomplish this by first filling the entire casing with sand or gravel 7 to a height sufficiently above the gas-bearing stratum to make it impossiblefor the gas to blow it out, as illustrated in Fig. 2. The

casing is then drawn up sufiicient'ly to bring.

its lower end above the bottom and'preferably above the top of the gas bearing stratum, as shown in Fig. 3, thus permitting the gasto pass directly into the lower end of the pipe. The gas-permeable instrumentality which has been inserted into the casing completely fills the boreof the well after the withdrawal of the casing and prevents thesand and gravel in the gas-bearing stratum from being blown out. *If the sand and gravel should perchance have been blown out or partially blown out, so as to remove the support for the overlying clay and permit it to fall, as shown in Fig. 4, the drill is driven down through the gas-bearing stratum and into the underlying clay, as illustrated cavity in the underlying clay, as seen in 5 Fig. '5, the action of the water being assisted by thev p'ressurehnd assage of the gas throu h 'it -'I he water en bailed out ands cient sand or gravel 7 put downthe casing to fill the bore of the well to a point above the gas-bearing stratum and the bottom of the casing. The sand or gravel will fill up the passage between the overlying and underlying clay with a gaspermea'ble filling, so'that the overlying clay will not fall and the gas will pass freely through the filling into the casing.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The method of well construction for natural-gas wells which consists in sinking a casing to the gas-bearing stratum, then boring a communicating bore or hole through the gas-bearing stratum and into the stratum underlying it, and then filling the hole with gas-permeable material.

2. The method of well construction for natural-gas wells which consists in sinking a casing through the gas-bearing stratum and removing the material within the casing, then filling the casing to a point above the bottom of the gas-bearing stratum with gaspermeable material, and then withdrawing the casing above the bottom of the gas-bearing stratum. I

3. The method of Well construction for natural-gas wells which consists in sinking a casing through the gas-bearing stratum and removing the material within the casing, then inserting in the casing a gas-permeable filling, and withdrawing the casing above the bottom of the gas-bearing stratum.

4. The method of well construction for natural-gas wells which consists in sinking a casing to the gas-bearing stratum, then drilling a communicating bore or hole through said stratum, then removing the drill, then washing out said bore or hole and the Walls of the adjacent strata, then removing the water, and then filling said hole and the washed-away portions of the adjacent strata with gas-permeable material.

In testimony whereof I afiix my signature in presence of two witnesses.

DAVID M. SWAIN.

Witnesses ARTHUR P. LOTHROP, EMILY F. OTIs. 

